Does Replacing a Hot Water System Need an Electrician in QLD?

Byron Knight, Licensed Electrical Contractor

QLD Lic. 1511406 · 20+ years’ experience · Gold Coast & SEQ · Updated September 2026

The plumber quoting your hot water changeover says he can do the whole job. A mate tells you that you’ll need a sparky as well. Both of them can be right, and which one applies to your job has almost nothing to do with the tank sitting against your wall.

Queensland draws the line in a place most homeowners never hear about — a licence category that lets some plumbers do some electrical work, and stops flat at a boundary that a lot of hot water jobs cross without anyone mentioning it. This guide sets out where that line sits, what paperwork you should walk away with, and the one tariff decision that can quietly cost you money every quarter for the next decade.

It depends on what changes, not on what’s being replaced

A hot water changeover is two trades stacked on top of each other. The water side — the tank, the valves, the pipework, the relief drain — is plumbing work. The wiring side is electrical work. That much is obvious.

The part that isn’t obvious is that Queensland splits electrical work itself into two categories, and the split is what decides your answer. Work performed on a piece of electrical equipment is treated differently from work performed on the electrical installation — the fixed wiring, circuits, protective devices and switchboard that feed it.

So the useful question is not “is my new system electric?” It’s: does this job touch the fixed wiring, or only the appliance at the end of it?

What a plumber’s restricted electrical licence actually covers

Queensland issues a licence class called a restricted electrical work licence. WorkSafe Queensland describes these as licences that “authorise the performance of electrical work incidental to a trade or calling” — and the list of trades it gives includes, in as many words, “plumbers working on hot water systems”.

That’s the half of the story the plumber is telling you. Here’s the half that rarely gets mentioned. The same page states plainly: “A restricted electrical work licence does not permit electrical installation work.”

Read together, those two lines answer the question the whole internet argues about. A restricted licence exists precisely so a plumber can deal with the electrical connection that is incidental to the plumbing job in front of him. It does not turn him into an electrician, and the moment the job stops being a connection and becomes installation work, it is outside that licence regardless of who is holding it.

Where the line falls on a real changeover

Most hot water replacements fall cleanly on one side of this or the other. The table below is the practical version of the rule above.

Read down that list and something becomes clear. The genuinely like-for-like swap — same unit type, same position, same current draw, same tariff, sound existing wiring — is the only row where the question is even open. Everything else is installation work, and installation work needs a licensed electrician.

In practice the “like-for-like” swap is rarer than people expect. Tanks get replaced because they failed after fifteen or twenty years, and a lot changes in fifteen or twenty years: the model is discontinued, the replacement has a different element rating, the circuit predates modern RCD requirements, or the owner takes the opportunity to move off an old tariff. Any one of those turns the job into electrical installation work.

The paperwork you should get, and what it’s called

Queensland doesn’t rely on trust here. Under the Electrical Safety Regulation 2013, electrical work generates a certificate, and there are two of them: a certificate of testing and safety for work on electrical equipment, and a certificate of testing and compliance for electrical installation work.

WorkSafe QLD is specific about how it works. The certificate goes to “the person (or organisation) who engaged you (the licensed electrical contractor) to perform the work” — that’s you, the owner — and it must be given “as soon as possible after you complete the work”. The contractor also has to keep a copy for five years.

For a hot water changeover that involved the fixed wiring, the certificate of testing and compliance is the one that matters. It is your evidence that the circuit was tested, not just connected, and it is the document that gets asked for when a property is sold, when a landlord’s obligations are questioned, or when an insurer looks at a claim involving the system. We’ve covered the full picture in our guide to when you need an electrical compliance certificate in QLD.

The off-peak decision that outlives the tank

This is the part of a hot water replacement with the longest financial tail, and it is almost never discussed at quoting stage.

Most Queensland electric storage systems don’t run on your normal tariff. They sit on an Energex controlled load — Tariff 31 (Volume Controlled Night, also called Super Economy or CL1), which supplies power for 8+ hours, around 10pm to 7am, or Tariff 33 (Volume Controlled, or Economy, CL2), which gives 16+ hours, usually outside 4pm to 9pm. Cheaper energy, in exchange for the network choosing when it flows.

Two things follow from that, and both land on the electrician:

• Energex’s own instruction to customers is direct: “Please contact a licensed electrician and ask them to connect your appliance to an economy tariff.” The tariff connection is electrical work, not plumbing, and not something the retailer arranges on your behalf.
• If your new system is coming off the controlled load and it was the last appliance on it, Energex says your electrician “should also submit an Electrical Work Request to us so that the load control hardware in your meter box is removed”. Skip that step and you leave hardware and a supply arrangement in place that no longer matches your house.

The failure mode is quiet and expensive. A homeowner replaces a Tariff 31 storage unit with something that needs continuous supply, the tariff side gets handled loosely, and the hot water load lands on the general tariff at general tariff rates. The tank works perfectly. The bill is the only symptom, and by the time it’s noticed, a quarter or two has gone by. It’s one of the first things we check when someone asks why their power bill is so high.

Heat pumps and solar bring a second licence into it

If you’re replacing an electric storage unit with a heat pump or a solar system, there’s a Queensland requirement that catches people out. Business Queensland states that “solar hot water and heat pump hot water systems must be installed by a hot water installer with a solar and heat pump endorsement from the Queensland Building and Construction Commission (QBCC)” — an endorsement over and above an ordinary plumbing licence, and separate again from the electrical side, which changes too: different supply requirements, usually a different circuit, and a tariff decision that has to be made deliberately rather than inherited.

We’ve set out what actually changes electrically in our guide to electric hot water systems and heat pump conversion. The short version for this page: a heat pump changeover is never the “like-for-like” row in the table above.

What the plumber is doing on the same job

None of this means you don’t need a plumber. You do, and their side carries its own obligations that are worth knowing about.

1. It’s notifiable work. QBCC lists “installing or replacing hot water heaters including electric, solar or heat pumps” as notifiable plumbing work. The licensed plumber must lodge a Form 4 with QBCC within 10 business days, and give you a copy.
2. A temperature control device is mandatory. Business Queensland is unambiguous: “A temperature control device must be fitted to all new and replacement hot water systems.” It isn’t optional on a replacement because the old one didn’t have one.
3. The temperatures are set by rule, not preference. Water must be stored at a minimum of 60°C to suppress Legionella, and delivered to taps at a maximum of 50°C. Those two numbers are why the tempering device exists.

So a well-run changeover on a Queensland home produces a small stack of paper: a Form 4 from the plumber, and an electrical certificate from the electrical contractor for whatever electrical work was done. If you finish the job holding neither, something was skipped.

On the Gold Coast, specifically

Two local patterns shape how these jobs go here.

The first is housing age. A large share of the established stock across Southport, Labrador and the older pockets of Palm Beach was wired well before current RCD requirements, and the hot water circuit is frequently one of the last unprotected ones in the house. When the tank goes, that circuit is exposed for the first time in years. It is the cheapest moment you will ever get to bring it up to standard, because the access is already open — and it’s a question worth asking before the new unit goes on the wall, not after.

The second is tenure. The Gold Coast runs a high proportion of rentals and strata-titled units, which means the person organising the replacement is often not the person who will be living with it. Owners and managers need the certificate for their records, and in a unit block the hot water system may sit in common property or feed off a supply arrangement that isn’t as simple as a freestanding house. If that’s your situation, our strata and body corporate electrical page covers how those jobs are handled.

And salt air does the rest of the work. Coastal properties from Main Beach down to Currumbin see corrosion on external connections and isolators far faster than inland homes — so on an outdoor installation, the connection point deserves as much attention as the tank it’s feeding.